STATEMENT OF PRIOR ART
Heretofore, adding liquid catalysts or agents to the fuel supply of an engine, for effecting chemical reactions in the exhaust system, has been substantially a laboratory or prototype experiment. The prior art has recognized that soot, collected from the exhaust gases of a diesel engine, can be more readily removed or eliminated by oxidation if the exhaust gas carries an agent which codeposits with the soot and depresses or catalyzes the ignition temperature of the soot. It is the hope of such technology that during certain driving cycles of the automobile the exhaust temperature will rise to the depressed particulate ignition temperature and cleanse the soot trap, (see copending U.S. application Ser. No. 685,921, filed 12-24-84 assigned to the assignee of this invention, the disclosure of which is incorporated herein).
Most disclosures, in outlining utility for the liquid fuel additives, schematically point to a station at which the additive or agent can be added to the fuel supply without disclosing a dispensing mechanism that would carry out such function (see, for example, U.S. Pat. No. 3,370,419). To be successful, such mechanism must be (a) capable of reliably and automatically maintaining a uniform concentration of the additive in the fuel supply, (b) compensate for excessive residues due to possible interaction between the additive and other impurities in the diesel fuel, and (c) compensate for and prevent possible damage to other automotive components in the event of failure of the dispensing apparatus.